Coupling apparatus



FIG. 1 is a perspective view of a coupling apparatus showing a new design;

FIG. 2 is a right side elevational view thereof, the left side being a mirror image;

FIG. 3 is top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a front elevational view thereof; and,

FIG. 6 is rear elevational view thereof. 

CLAIM The ornamental design for a coupling apparatus, as shown and described. 